What does Isaiah 22:23 mean?
Sometimes the servant to a king will serve with such reliability, integrity, and wisdom that the king is happy to give that servant more authority and power to speak in his name. The Lord, through His prophet Isaiah, declares that Eliakim will be that kind of trusted servant (Isaiah 22:20–22).The word picture Isaiah uses is of a peg attached to the wall so securely that a significant amount of weight can be hung from it without worry of it coming crashing down. The other picture is that Eliakim will become like a throne that a king sits upon. In both pictures, the king can lay his burdens upon his servant and trust that they will be well handled.
All of Judah will benefit from having such a man in that position during this time in the history of God's people.